Ouvrage Galgenberg forms a portion of the Fortified Sector of Thionville of the Maginot Line. It is situated in the Cattenom Forest, near the gros ouvrage Kobenbusch and petit ouvrage Oberheid. The ouvrage was tasked with controlling the Moselle valley and as such was called the "Guardian of the Moselle." Galgenberg did not see significant action in 1940 or 1944. After a period of reserve duty in the 1950s and 1960s it was deactivated. It is now a museum.